Robert Digby was a well-educated, middle-class private in the British Expeditionary Force at the beginning of World War I. In the very first month of the war, as the British, French and German armies surged back and forth across tracts of northern France, he became isolated behind enemy lines. When the fluid front lines of the war’s first phase rapidly hardened into the murderous stalemate of the trenches, Digby and other British soldiers were permanently trapped in German-occupied territory. Seven, including Digby, took refuge in the small village of Villeret and were given shelter and assistance by the villagers. Under the noses of the German occupiers, they lived in Villeret for 18 months, masquerading as villagers. Relationships between the French peasants and the British soldiers grew strong.

Digby fell in love with Claire Dessenne, the 19-year-old daughter of one of his protectors. In November 1915 Claire gave birth to Digby’s daughter. Six months later someone in the village betrayed the men to the Germans. Digby and three others were captured, tried as spies and executed by firing squad. Digby’s daughter, now in her 80s, still lives in northern France. Using her memories and those of other villagers, archive material and a handful of surviving letters by Digby (including one written to Claire only hours before his execution), Macintyre has produced a real-life story of the First World War as poignant and moving as Sebastian Faulks’s novel Birdsong. —Nick Rennison